SQL UPDATE Statement

The UPDATE statement modifies existing rows in a table. It is one of the core Data Manipulation Language (DML) commands.

Syntax

UPDATE table_name
SET column1 = value1,
    column2 = value2,
    ...
[WHERE condition]
[ORDER BY column]
[LIMIT number_of_rows];

Basic Example

Update the Salary of employees in the Employees table.

UPDATE Employees
SET Salary = Salary * 1.10
WHERE Department = 'Sales';

Updating Multiple Columns

UPDATE Products
SET Price = Price * 0.9,
    Stock = Stock + 100
WHERE Category = 'Electronics';

Using Joins in UPDATE

Update rows based on a join with another table.

UPDATE Orders o
JOIN Customers c ON o.CustomerID = c.ID
SET o.Status = 'Processed'
WHERE c.Region = 'North America';

Common Pitfalls

Omitting the WHERE clause updates every row.
Using non‑deterministic expressions without proper indexing may cause performance issues.
Beware of data type mismatches that can cause implicit conversions.

Related Topics